ceph/doc/rados/operations/erasure-code-isa.rst

   1 =======================
   2 ISA erasure code plugin
   3 =======================
   4
   5 The *isa* plugin encapsulates the `ISA
   6 <https://01.org/intel%C2%AE-storage-acceleration-library-open-source-version/>`_
   7 library. It only runs on Intel processors.
   8
   9 Create an isa profile
  10 =====================
  11
  12 To create a new *isa* erasure code profile::
  13
  14         ceph osd erasure-code-profile set {name} \
  15              plugin=isa \
  16              technique={reed_sol_van|cauchy} \
  17              [k={data-chunks}] \
  18              [m={coding-chunks}] \
  19              [ruleset-root={root}] \
  20              [ruleset-failure-domain={bucket-type}] \
  21              [directory={directory}] \
  22              [--force]
  23
  24 Where:
  25
  26 ``k={data chunks}``
  27
  28 :Description: Each object is split in **data-chunks** parts,
  29               each stored on a different OSD.
  30
  31 :Type: Integer
  32 :Required: No.
  33 :Default: 7
  34
  35 ``m={coding-chunks}``
  36
  37 :Description: Compute **coding chunks** for each object and store them
  38               on different OSDs. The number of coding chunks is also
  39               the number of OSDs that can be down without losing data.
  40
  41 :Type: Integer
  42 :Required: No.
  43 :Default: 3
  44
  45 ``technique={reed_sol_van|cauchy}``
  46
  47 :Description: The ISA plugin comes in two `Reed Solomon
  48               <https://en.wikipedia.org/wiki/Reed%E2%80%93Solomon_error_correction>`_
  49               forms. If *reed_sol_van* is set, it is `Vandermonde
  50               <https://en.wikipedia.org/wiki/Vandermonde_matrix>`_, if
  51               *cauchy* is set, it is `Cauchy
  52               <https://en.wikipedia.org/wiki/Cauchy_matrix>`_.
  53
  54 :Type: String
  55 :Required: No.
  56 :Default: reed_sol_van
  57
  58 ``ruleset-root={root}``
  59
  60 :Description: The name of the crush bucket used for the first step of
  61               the ruleset. For intance **step take default**.
  62
  63 :Type: String
  64 :Required: No.
  65 :Default: default
  66
  67 ``ruleset-failure-domain={bucket-type}``
  68
  69 :Description: Ensure that no two chunks are in a bucket with the same
  70               failure domain. For instance, if the failure domain is
  71               **host** no two chunks will be stored on the same
  72               host. It is used to create a ruleset step such as **step
  73               chooseleaf host**.
  74
  75 :Type: String
  76 :Required: No.
  77 :Default: host
  78
  79 ``directory={directory}``
  80
  81 :Description: Set the **directory** name from which the erasure code
  82               plugin is loaded.
  83
  84 :Type: String
  85 :Required: No.
  86 :Default: /usr/lib/ceph/erasure-code
  87
  88 ``--force``
  89
  90 :Description: Override an existing profile by the same name.
  91
  92 :Type: String
  93 :Required: No.
  94